Sussex North Water Certification Scheme (SNWCS): What Developers Need to Know
Published by H2Ogeo | October 2025
The Sussex North Water Certification Scheme (SNWCS) — formerly known as the Sussex North Offsetting Water Scheme (SNOWS) — is due to launch in Autumn 2025, offering a new route for developers to demonstrate water neutrality compliance within the Sussex North Water Resource Zone (WRZ).
Jointly managed by Horsham District Council, Chichester District Council, Crawley Borough Council, Mid Sussex District Council, the South Downs National Park Authority and West Sussex County Council, SNWCS provides a streamlined, affordable certification process to help unlock sustainable development while safeguarding the Arun Valley SAC, SPA and Ramsar sites.
Purpose of SNWCS
The scheme’s central aim is to ensure that additional water demand from new development does not exceed the baseline water savings achieved through Southern Water’s Water Resources Management Plan 2024 (WRMP24).
This protects sensitive ecosystems by preventing further abstraction pressure on the Arun Valley.
While all developments in the Sussex North WRZ must prove water neutrality under the Habitats Regulations, joining SNWCS is optional. Applicants can either:
Apply for SNWCS certification, or
Deliver an independent offsetting strategy that meets equivalent neutrality requirements.
How the Scheme Works
At the planning application stage, developers can apply for SNWCS certification.
Applications will be prioritised according to available scheme capacity.
If accepted — and once the certification charge is paid — the scheme will confirm that the project can proceed in accordance with Habitats Regulations.
If capacity is unavailable, applicants will be notified and may pursue an alternative offsetting solution or await future capacity.
An early-access service is also planned post-launch to support pre-application engagement.
Certification Costs
The SNWCS access charge, approved at Horsham DC’s Cabinet Meeting (21 May 2025), will be set at:
£0.80 per litre of daily water use (one-off payment per certified development).
This charge reflects scheme operating costs only — Southern Water’s WRMP24 savings remain separately funded.
Which Developments Qualify?
Eligible projects are those consistent with:
Adopted or post-submission local plans
Made or post-examination neighbourhood plans
Allocated sites identified within authority-approved planning documents
Non-qualifying examples include:
Unallocated housing beyond settlement boundaries
Employment sites outside designated areas
Certain specialist developments (tourism, minerals, gypsy & traveller sites)
Most permitted development (with limited local-authority exceptions)
Preparing for Launch
With SNWCS expected to open later in 2025, developers and agents should now review their water use estimates and offsetting strategies. Early preparation will help ensure planning applications are ready once certification becomes available.
How H2Ogeo Can Help
H2Ogeo provides expert Water Neutrality Statements, water balance assessments, and offsetting calculations that comply with both SNWCS and bespoke mitigation pathways.
Our hydrogeological expertise ensures your application is technically robust, policy-aligned, and ready for submission.
📞 Contact H2Ogeo to discuss your site’s water neutrality strategy ahead of the SNWCS rollout.
